Well, now I am confused too! I never even had 154.77 in my scanner for some reason. I hear fire traffic regularly on 154.265 and 155.58. I frequently lock out 155.58 because of all the cop talk on there from Parker County (no PL in my conventional scanner). I'll stick 154.77 in and see if anything comes up. They are close enough that it shouldn't be a problem to hear if they are actually there.
I am not an avid listener of Ellis County. They are just one of many programmed into my conventional scanner that I monitor continuously for "the big one". Consequently, my word is certainly not gospel. Just another voice in the crowd. Other channels noted active in Ellis County:
151.460 Midlothian Fire (possibly Ovilla also?)
154.205 Ennis Fire & ETMC VHF Dispatch
154.220 Red Oak Fire
154.325 Ferris Fire
154.385 Waxahachie Fire (yes, they still sometimes use it apparently, because I hear them. Not sure of when or why.)
I hadn't heard anything on 46.46 in quite awhile, so I pulled it out, but I don't know for sure if it has been completely abandoned. Anybody else listen to it?
Also, remember that "Regional" (the combined DeSoto, Duncanville, & Cedar Hill fire departments) frequently responds mutual aid into Midlothian. By frequently, I mean almost every day. Midlothian actually abuses the relationship pretty badly, and I'm surprised that "Regional" doesn't tell them to F-off. They commonly call Cedar Hill just to go down and fill-in at their station when they are busy, even if there are no runs holding. They are on 155.925.
You'll also hear Lancaster (151.235) doing mutual aid with Midlothian, as well as with Regional.